Method and apparatus for dusting mold cores



F. DERROR 3,409,456

METHOD AND APPARATUS FOR DUSTING MOLD CORES Nov. 5, 1968 4 Sheets-Sheet 1 Filed Dec. 4, 1963 u. 4. 9 o... a H 0 .u w 9 v v. 1 O n. o '0 F I G. I

INVENTOR. FRED L. DERROR W W ATTORNEYS Nov. 5, 1968 F. L. DERROR METHOD AND APPARATUS FOR DUSTING MOLD CORES Filed Dec. 4, 1963 4 Sheets-Sheet 2 FIG.2

3! J INVENTOR. FRED L. DERROR ATTORNEYS F. L. DERROR 3,409,456

METHOD AND APPARATUS FOR DUSTING MOLD CORES Nov. 5, 1968 4 Sheets-Sheet 3 Filed Dec. 4, 1963 FIG.3

INVENTOR.

FIG.4

50 FRED L. DERROR m'p fifi ATTORNEYS Nov. 5, 1968 F. DERROR 3,409,456

METHOD AND APPARATUS FOR DUSTING MOLD CORES INVENTOR. FRED L. DERROR A BY ATTORNEYS United States Patent 3,409,456 METHOD AND APPARATUS FOR DUSTING MOLD CORES Fred L. Derro r, Lucas, Ohio, assignor to Mansfield Sanitary, Inc., Perrysville, Ohio, a corporation of Ohio Filed Dec. 4, 1963, Ser. No. 328,082

Claims. (Cl. 117-5.1)

ABSTRACT OF THE DISCLOSURE A mold core is sealingly received in a boot.

Dust from an atomizer is blown tangentially across the core from a plurality of orifices at one end of the boot. Thereafter, dust free air is admitted to the boot while an exhaust pump purges the boot through vents opposingly positioned with respect to the orifices so that thecore can be unsealed and removed without contaminating surrounding atmosphere.

The present invention relates generally to slip casting hollow ceramic shapes. More particularly, the present invention relates to slip casting hollow ceramic shapes in a mold with a removable core. Specifically, the present in- .vention relates to apparatus for dusting (preferably in multiple) the core utilized with a mold for slip casting hollow ceramic shapes.

To slip cast hollow ceramic shapes the liquid slip is poured into the cavity formed between the mold and a removable core. After the slip casts-i.e., loses its fluiditythe core may be removed and the casting permitted to green cure a suflicient time longer until it may be carefully extracted from the mold. It is readily apparent that the greatest efliciency may be obtained from each mold and core if the minimum cyclic time is utilized to complete the pouring of the slip, allow the slip to cast, remove the core, remove the green casting and pour the slip for a second casting. The novel system for slip casting hollow ceramic shapes disclosed in my copending US. Patent No. 3,189,971, is one by which the mechanical steps can be effected, limited only by the casting and curing times.

Along with the purely mechanical steps, an additional factor must be taken into consideration. That is, the variation'in the adhesion between the slip and the mold and core depending upon the degree of wettability of the mold and core.

Slip will firmly adhere to any wettable surface. Because of this, molds and cores have traditionally been made of a nonwettable substance, such as plaster of Paris, which is sufliciently porous to absorb the moisture from the slip as it casts. Cumulative absorption of water into the body of the mold and core from previous casting cycles, tends to reduce their capacity for continued absorption unless permitted to dry to a certain extent. Moreover, this ab- It is another object of the present invention to provide an apparatus into which a core may be inserted for automatic dusting.

It is still another object of the present invention to provide a dusting apparatus, as above, which deposits the dust uniformly across the entire surface area of the core with maximum adhesion of the dry dust to the core.

It is a further object of the present invention to provide a dusting apparatus, as above, into which the core may be inserted, dusted and Withdrawn without expelling dust into the surrounding atmosphere.

It is a still further object of the present invention to provide an apparatus, as above, capable of simultaneously dusting a plurality of cores.

These and other objects of the invention, as well as the advantages thereof over existing and prior art forms, will be apparent in view of the following detailed description sorption also tends to cause a slight adhesion between the slip and the mold and core proportionate to the degree of the residual moisture content. Thus, if the mold were to dry to a greater degree than the core, the casting could accidently be withdrawn from the mold as the core is extracted. To obviate the possibility of inadvertent adhesion of the casting to the core through successive recyclings, the cores are dusted with a material such as talc, which supplementarily reduces the adhesion therebetween.

However, the dust, when applied dry, does not readily adhere ot the core, and to apply it suspended in a liquid spray causes undesirable build-up on the core over successive applications.

It is therefore an object of the present invention to provide an apparatus for applying substantially dry dust to the cores.

and the attached drawings and are accomplished by means hereinafter described and claimed.

One preferred embodiment is shown by way of example in the accompanying drawings and hereinafter described in detail without attempting to show all of the various forms and modifications in which the invention might be embodied; the invention being measured by the appended claims and not by the details of the specification.

In the drawings:

FIG. 1 is an end elevation of the dusting apparatus of the present invention positioned to receive a plurality of cores mounted on a carriage, as disclosed in my aforementioned US Patent application, Serial No. 278,345;

FIG. 2 is a partial rear elevation taken substantially on line 2-2 of FIG. 1;

FIG. 3 is an enlarged cross section taken substantially on line 3-3 of FIG. 2;

FIG. 4 is a schematic flow diagram of the dusting apparatus;

FIG. 5 is a cross sectional view of a core insertably received within a dusting boot; and,

FIG. 6 is a partial top plan taken substantially on line 66 of FIG. 2.

In general, an apparatus for dusting cores according to the concept of the present invention utilizes a boot into which the core is insertably received. A sealing means around the opening of the boot engages the core and prevents escape of dust into the surrounding atmosphere. An input manifold interiorly of the boot receives dust from an atomizer and is provided with a plurality of apertures through which the dust is blown under pressure into the boot by an input pump. A similar exhaust manifold is positioned in opposition to the input manifold and is connected to an exhaust pump which applies a vacuum to the interior of the boot via a plurality of vents in the exhaust manifold to withdraw the dust from the boot. Withdrawal of the dust is facilitated by a selectively operative purge line which bypasses the atomizer and connects the input pump directly to the input manifold. In this way dust free air is admitted to the boot at the same time the dust is being evacuated so that little or no dust is permitted to escape into the surrounding atmosphere at the end of the dusting operation when the core is withdrawn from the boot.

Referring more particularly to the drawings, a dusting apparatus, indicated generally by the numeral 10, comprises a plurality of individual dusting elements joined simultaneously to dust a plurality of cores, as for example, when used in conjunction with the apparatus and system of my aforesaid US. Patent No. 3,189,971.

As shown in FIG. 1, the dusting apparatus 10 is movable on an overhead track 12 to be selectively positionable with respect to carriage 13 and the plurality of cores 14 carried thereon. The cores 14 are supported between a pair of stanchions 1'5 and are lowered and raised by a winch means 16.

The dusting apparatus is supported by vertical beam 18 dependingly extending from truck 19, the wheels of which permit it to move along track 12. A pair of upper knee braces 21 extend between the dependingsupport beam 18 and the truck 19 to impart a rigidity to the dusting apparatus ,Near the,lower extremity of the depending vertical beam 18 a pair of wing plates 22.and 23 extend perpendicularly outwardly of beam 18 and attach to,a rectangular box frame comprised of sidemem-bers 24 and 25 spaced apart by .end members 26. The box frame may also be stabilized by a pair of lower braces 26a extending between the side member 24 and the vertical beam 18.

A plurality of pairs of. cantilevered-brackets "29 vand 30 extend perpendicularly forwardly of the outer side member 24 and each pair supports a boot 31. therebetween.

As best shown in FIGS. and 6, the boot 31 has four side walls 32 extending upwardly from a base portion 33 and terminating in a seating-flange 34 around the periphery of the open end. A sealing means-35, such as a felt or rubber strip, is positioned around the periphery of the seating flange 34 and engages the cap portion 36 of-the core 14 when the core is insertably received in the boot Mounted in proximity to the base portion, or closed end, 33 of the boot 31 is an input manifold 39. The input manifold 39 extends around the periphery of the base portion 33 adjacent the side walls 32 and is provided with a plurality of apertures or orifice means 40. Some of the orifices 40A are upwardly directed so that dust emanating therefrom will impinge primarily onthe sides 41 of the core 14. Other of the orifices 40B arelaterally, or horizontally directed so that dust emanatingtherefrom will impinge primarily on the underside 42 of core 14.-To effect theoptimum adherence of the dust to the core the dust is directed substantially tangentially across thesurface of the core. It has been found. that the best results are obtained if the dust impinges upon the core at an angle tothe core surf-ace no greater than The input manifold is connected by an input.feed pipe, tubing or other suitable communicating means, 43 (FIG. 1) to an atomizer, indicated generally by the numeral 44. As shown,in FIG.- 3, the atomizer 44 is comprised of a hollow, preferably cylindrical canister housing 45 with the top plate,46 sealed thereto to forman airtight reservoir 48. This reservoir 48 holds the dust which is sprayed onto the core -14. For filling the reservoir a fill tube 49 is provided through the top plate 46- and is itself sealed with a cap 51.

Near the bottom of the reservoir 48 a deflection plate, such as the conical plate 52 shown, is provided and may be attached to lie' angularly between the base 53 and the side wall 45 of the cylindrical canister housing 45.

A nozzle 50 within the atomizer is fed through a terminal pipe 55 from an input air pump 56(FIG. 1). The nozzle has one or more'restricted discharge orifices 54 directed to discharge against the deflection plate 52in order that assured turbulenc'e'can be created within the reservoir to effect the greatest suspension of dust in the airwhich -then passes outwardly of the reservoir 48 through a fine mesh screen" 58 into the communicating pipe 43 to the input manifold 39.

As is best seen in FIG. 2, a plurality of atomizers 44 are positioned generally beneath the box frame side member 24, one for each of the plurality of boots 31. All the atomizers 44 can be operated by a single input air pump 56.

A master feed pipe 59 extends downwardly along the vertical beam 18 from the input air pump 56 and connects 'to an input header 60. The terminal pipe 55 for each 'atomizer'44 connects to the input header 60 for its air supply.

An exhaust manifold 61 is also provided in the boot 31. The exhaust manifold 61 is similar to input manifold 39 and is similarly placed adjacent to side walls 32 around the periphery of the opposite end of the boot 31 from the input manifold 39.

In the disclosed apparatus, which utilizes a plurality of boots 31, the exhaust manifold 61 in each boot communicates with the single exhaust header 62" by-a connector pipev63 (FIG. 2). The exhaust header 62 is in turn connectedto an exhaust, oryacuurn, pump 64.

The operation of the exhaust pump 64'draws'the air out of the boot 31 through a pliirality' of horizontally disposed vents 65 along the inner side of the exhaust manifold 61. By placing the input and exhaust manifolds in opposed relation, i.e.,at opposite endsof'the core to be dusted, a flow pattern is createdwhich assuresthatdustentrained air will engulf the :entire core.m a

Because of the extreme efiiciency of the present dust-1 ing apparatus it can be usedv to adequately dust a plurality of cores automatically in a matterof'secondsyand. a suggested preferred control system. is. shown in F'IGJ4.

A trigger, or master switch, 68 initiates the =dusting cycle. The master switch'68 is ponnected toactuate three slave time delay relays 69,70 and 71 which are connected in parallel from the master switch'68. Relays 69, '70 and 71 are standard time delay ontypes in that theyeachactuate a solenoid operated valve to open, remain open and close after predetermined time. Specifically, relay 69 is wired to actuate valve 72 in the input line. Legs 73 and 74 of the input line schematically represent the'con-- nector pipe 59 shown in the detail drawings and may be supplied with such standard items as a pressure gauge '75 and a pressure regulator 76. Leg 74 is also represented as being in communication with theinput header '60-. l

Simultaneously with the opening of valve 72, relay 70 opens valve 78 which is also located in leg 731 With these two valves open the air is pumped through the connector pipe 59 and header 60, and thence through atomizer '44 and into the boot 31 via the input manifold 39. i

As was described above, the dust containingair'enten ing the boot 31 is aided in its circulation around and past core 38 by exhausting through manifold 61, which is accomplished by the simultaneous opening ofvalve 79. in

the line 80 between the exhaust header 62 and the exhaust pump 64.

As exemplary timings the relay'70m'ay be a fivesecond delay relay so that the valve 78 remains'ope'n'for five seconds before it closes, and the relay 69 may be a two second delay relay so that valve 72 remains openonly for two seconds. Thus, the pressurized air is permitted to pass through the atomizer 44 for two seconds after which the valve 72 is closed and the pressurized air bypasses the atomizer 44 via a purge line '81 directly into the boot 31 through the input manifold 39.

Of course, in the multiple dusting operation disclosed a purge line 81 may be supplied for each boot 31 and be fed through a purge header 82 which is inturn connected to the conector pipe 59 by a'line 83 (FIG. 6). At the end of five seconds valve 78 closes and no further air is admitted into the boot 31.'However, relay71 which is' preferably of longer delay than either'relay 69 or 70 permits the valve 79 to remain open for preferably fifteen seconds. During the additional ten seconds tha t valve" remains open the vacuum applied to the i nterior of the boot willexhaust the remainder of the dustent raiued air so that when the valve 79 closes the core may be removed without expelling dust into. the surrounding. atmosphere.

In the particular embodimentdescribed it has been found that the input pump should provide about thirty pounds per square inch line pressure and that'the exhaust pump should draw approximately an' eight inch vacuum for the times noted above; however, the particular pressures and times may be widely altered to suit a particular adaptation.

It should be apparent that theapparatus disclosed accomplishes the objects of the invention.

What is claimed is:

1. An apparatus for dusting cores comprising, a boot means, said boot means having a closed base portion at one end thereof and an open portion at the other end thereof through which a core may be insertably received in said boot means to define a space therebetween, sealing means between said core and the open end of said boot means, orifice means at one end of said boot means for introducing dust into said space and substantially tangentially across said core, and vent means in substantial opposition to said orifice means in said boot means to remove dust.

2. An apparatus for dusting cores comprising, a boot into the interior of which a core is receivable to define a space therebetween, orifice means on the interior of said boot, a dust atomizer communicating with said orifice means, pump means for blowing dust from said atomizer through said orifice into said space, bypass means connecting said pump means directly to said orifice means, valve means for selectively opening and closing said bypass means, vent means in said boot substantially opposed to said orifice means to remove dust, and mechanical means interpositioned of said boot and a core received therein to provide a dust seal between said space and the surrounding atmosphere.

3. An apparatus for dusting cores comprising, a boot into the interior of which a core is receivable, said boot having a base at one end and an opening at the other end thereof through which a core may be insertably received in said boot to define a space therebetween, sealing means between the core and the opening of said boot, an input manifold at one end of said boot, a plurality of orifices in said manifold directed into said space and substantially tangentially across the core, a dust atomizer communicating with said input manifold, pump means for blowing dust from said atomizer through said input manifold out of said orifices and into said space, and vent means in said boot in opposition to said orifices to remove dust.

4. An apparatus for dusting cores as described in claim 3 in which the orifices impinge the dust on said core at an angle no greater than and the vent means comprises an exhaust manifold with a plurality of vents communicating with said space, said exhaust manifold being opposed to the input manifold, and an exhaust pump means communicating with said exhaust manifold.

5. An apparatus for dusting cores comprising, a boot means into which a core is receivable to define a space therebetween, orifice means at one end of said boot for introducing dust into said space substantially tangentially across a core and, selectively, dust free air, vent means in said boot substantially opposed to said orifice means, exhaust means to withdraw dust-laden air from said space through said vent means, and mechanical means extending between said boot and a core received therein substantially to preclude dust from exiting from said space into the surrounding atmosphere.

6. An apparatus for dusting cores comprising, a boot, said boot having a base portion and substantially vertical side walls terminating in an open end through which a core may be insertably received, sealing means between the core and the opening of said boot to define a space between the base portion and sidewalls of said boot and said core, an input manifold adjacent the base portion of said boot, a plurality of substantially vertically and horizontally disposed orifices in said input manifold directed into said space, a dust atomizer communicating with said input manifold, input pump means for blowing dust from said atomizer into said input manifold, through said orifices and into said space substantially tangentially of said core, an exhaust manifold positioned at the other end of said boot in opposition to said input manifold, a plurality of vents in said exhaust manifold communicating with said space, and an exhaust vacuum pump communicating with said exhaust manifold to remove dust.

7. A core dusting apparatus, as described in claim 6, in which the vents are substantially horizontally disposed.

8. A core dusting apparatus, as described in claim 6, in which the atomizer comprises, a dust reservoir, the interior of said dust reservoir communicating with said input manifold, a nozzle interiorly of said reservoir, a deflection plate, said nozzle connected to said input pump means and directed toward said deflection plate.

9. A method for dusting cores comprising the steps of, inserting a core into a boot, sealing the core within said boot so as to provide a space between the outer wall of said core and the inner wall of said boot, blowing dus into said space and onto the outer wall of said core from a position substantially tangentially of said core, applying a vacuum to said space from a position substantially opposed to the position from which dust is blown into said space, ceasing to blow dust into said space, purging said space of excessive dust by admission of dust free air during continued application of vacuum to said boot space, and withdrawing said dusted core.

10. A method for dusting cores comprising the steps of, inserting a core into a boot, sealing the core within said boot so as to provide a space between the outer wall of said core and the inner wall of said boot, blowing dust into said space and onto the outer wall of said core from a position substantially tangentially of said core, applying a vacuum to said space from a position substantially opposed to the position from which dust is blown into said Space, purging said space of excessive dust by admission of dust free air during continued application of vacuum to said space and simultaneously therewith ceasing to blow dust into said space, ceasing the application of purge, after a predetermined delay ceasing the application of vacuum, and withdrawing the dusted core.

References Cited UNITED STATES PATENTS 2,795,512 6/1957 Sherratt et al 117-53 2,815,550 12/1957 Valyi.

2,844,489 7/ 1958 Gemmer 11721 X 2,987,413 6/ 1961 Dattling et al 11721 3,004,861 10/1961 Davis 117-21 X 3,032,816 5/1962 Zirnmerli 11721 X 3,063,860 11/1962 Gemmer.

3,108,022 10/ 1963 Church 117-21 X 3,166,439 1/ 1965 Dennhofer 1189 3,196,033 7/1965 Brooks 1l721 3,208,868 9/1965 Stroebel et a1 1183l2 X 3,208,869 9/1965 Starr et al 11721 X WILLIAM D. MARTIN, Primary Examiner.

P. F. ATTAGUILE, Assistant Examiner. 

